Adaptive virtual function drivers for electronic devices

ABSTRACT

Techniques for providing adaptive virtual function (VF) drivers capable of operating with physical devices having a plurality of different hardware configurations are described. In one embodiment, for example, an apparatus may include logic to implement a virtual machine (VM), the logic to initialize an adaptive virtual function (VF) driver to facilitate communication between the VM and a physical device to be virtualized, establish communication between the adaptive VF driver and a physical function (PF) driver of the hypervisor for the physical device, activate a standard feature set for the adaptive VF driver to execute on a PF of the physical device, and negotiate activation of an advanced feature set for the adaptive VF driver to execute on the PF, the adaptive VF driver to provide the advanced feature set to the PF, the PF activate each feature of the advanced feature set supported by the PF.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 62/513,625, filed on Jun. 1, 2017, entitled “Adaptive VirtualFunction Driver for Electronic Devices,” the content of which isincorporated herein by reference.

TECHNICAL FIELD

Embodiments herein generally relate to information processing and, morespecifically, but not exclusively, to techniques for management ofadaptive virtual function drivers in a virtualization computingenvironment.

BACKGROUND

Advancements in networking have enabled the rise in pools ofconfigurable computing resources. These pooled configurable computingresources may be formed from a physical infrastructure includingdisaggregate physical computing resources, such as, for example, largedata centers. The physical infrastructure can include a number ofcomputing systems having processors, memory, storage, networking, power,cooling, etc. Management entities of these data centers may provisioncomputing resources to a computing entity (for example, containers,virtual machines (VMs), or the like) to allocate portions of the pool ofconfigurable computing resources to support, implement, execute or run aworkload, such as, an application within the virtual computing entity.

Various types of applications or application workloads may utilize thisallocated infrastructure in a shared manner, for example, viavirtualization of resources. In general, virtualization involves the useof computer software and hardware to emulate or otherwise implement thefunctions or features of a physical computing device to allow, amongother things, sharing of physical computing resources. For example,multiple virtual machines (VMs) can run concurrently on the samephysical computing system. In the context of input-output (I/O) devices,virtualization technologies can be used to allow multiple VMs to sharethe same I/O hardware resources

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an embodiment of a first operating environment.

FIG. 2 illustrates an embodiment of a second operating environment.

FIG. 3 illustrates an embodiment of an adaptive component hierarchy.

FIG. 4 illustrates an embodiment of a third operating environment.

FIG. 5 depicts an illustrative logic flow according to a firstembodiment.

FIG. 6 illustrates an example of a storage medium.

FIG. 7 illustrates an example computing platform.

DETAILED DESCRIPTION

Various embodiments may generally be directed toward systems andtechniques for configuring, deploying, or otherwise managing domainsand/or containers within a virtualized computing environment. Domainsand/or containers may include virtual machines (VMs) and/or componentsthereof, such as drivers. In some embodiments, VMs may be operative toinclude adaptive components, such as adaptive drivers operative to beforward compatible with virtualized hardware resources.

Data centers may generally be composed of a large number of racks thatcontain numerous types of hardware or configurable computing resources.For example, the racks can contain central processing units (CPUs),graphics processing units (GPUs), memory, storage, networking,fans/cooling modules, power units, or the like. The types of hardware orconfigurable computing resources deployed in data centers may also bereferred to as disaggregate physical elements. The size and number ofcomputing resources and the disaggregation of these resources presentscountless combinations of computing resources that can be configured tofulfill workloads. Also, the types of workloads may have differentcharacteristics that may require a different mix of computing resourcesto efficiently fulfill a given type of workload.

Deploying, supporting, configuring, maintaining and provisioning suchpools of configurable computing resources can be a challenge. Onechallenge in particular concerns hardware-supported virtual functions,such as single root input/output (I/O) virtualization (SR-IOV)functions, among others. By way of example, the SR-IOV interface is anextension to the PCI Express (PCIe) specification. SR-IOV allows adevice, such as a network adapter, to separate or partition access toits resources among various PCIe hardware functions. These functions mayinclude, for example, a PCIe Physical Function (PF). The PCIe PF is aprimary function of a device and advertises the device's SR-IOVcapabilities. In some embodiments, a PCIe PF may be associated with ahypervisor or virtual machine manager (VMM) (for instance, Hyper-Vparent partition) in a virtualized environment. Another PCIe hardwarefunction may include one or more PCIe Virtual Functions (VFs). Invarious embodiments, a VF may be associated with a device's PF. A VF mayshare one or more physical resources of the device, such as a memory anda network port, with the PF and other VFs on the device. In someembodiments, a VF may be associated with a VMM (for instance, Hyper-Vchild partition) in a virtualized environment.

Each PF and VF may be assigned a unique PCI Express Requester ID (RID)that allows an I/O memory management unit (IOMMU) to differentiatebetween different traffic streams and apply memory and interrupttranslations between the PF and VFs. This allows traffic streams to bedelivered directly to the appropriate VMM (for instance, Hyper-V parentor child partition). As a result, nonprivileged data traffic flows fromthe PF to VF without affecting other VFs.

SR-IOV enables network traffic to bypass the software switch layer ofthe VMM (or Hyper-V) virtualization stack. Because the VF is assigned toa child partition, the network traffic flows directly between the VF andchild partition. As a result, the I/O overhead in the software emulationlayer is diminished and achieves network performance that is nearly thesame performance as in nonvirtualized environments.

One problem associated with hardware supported virtual functions (e.g.SR-IOV virtual functions), is that the virtual functions are directlyassigned to a particular virtual machine (VM). Furthermore, each VMand/or VF is typically specific to a hardware implementation and also tothe hardware PF. As such, every change in a given hardware platform fora VM may necessitate a change in one or more network virtual functiondrivers associated with the VM.

For instance, cloud service providers may have thousands of VMs runningin a data center. These VMs typically run a fixed set of operatingsystem (OS) images or OS image is brought in by the customers ortenants. Cloud service providers periodically upgrade the servers,networks, and/or components thereof. If the device drivers in the VMsare tied to specific hardware, then upgrading hardware could meanupdating the virtual function drivers in each of the VMs. This makes theupgrade process cumbersome, inefficient, and costly for the serviceprovider. When creating VMs, it would be ideal for the cloud vendors tocreate a hardware agnostic image and be able to install this image onany system, even those with a newer I/O device in them. Accordingly,some embodiments provide a virtual function driver that does not need tobe updated when the underlying hardware is changed, unless, forinstance, a vendor or other entity would like to use the new featuressupported by the new hardware.

FIG. 1 illustrates an example of an operating environment 100 that maybe representative of some embodiments. As shown in FIG. 1, operatingenvironment 100 may include a virtualized computing environment having acomputing device 120, for instance, implemented as processor-basedplatform configured to execute a VMM 110. Although implemented insoftware, VMM 110 may emulate and export a virtual machine interface tohigher level software. Such higher level software may comprise astandard OS, a real time OS, or may be a stripped-down environment withlimited OS functionality and may not include OS facilities available ina standard OS in some embodiments. Alternatively, for example, the VMM110 may be run within, or using the services of, another VMM. VMMs maybe implemented, for example, in hardware, software, firmware, and/or anycombination thereof. In at least one embodiment, one or more componentsof the VMM 110 may execute in one or more virtual machines and one ormore components of the VMM 110 may execute on the platform hardware asdepicted in FIG. 1. The components of the VMM 110 executing directly onthe platform may be referred to as host components of the VMM 110. Inanother embodiment, examples of VMM 110 may comprise a hybrid virtualmachine monitor, a host virtual machine monitor, or a hypervisor virtualmachine monitor.

The computing device 120 may include various logic devices. Non-limitingexamples of computing devices 120 may include a personal computer (PC),a server, a mainframe, a handheld device such as a personal digitalassistant (PDA), a tablet, a smart phone or any other smart devices, anInternet Protocol device, a digital camera, a portable computer, ahandheld PC such as netbook or notebook, an embedded applications devicesuch as a micro controller, a digital signal processor (DSP), a systemon a chip (SoC), a network computer (NetPC), a set-top box, a networkhub, a wide area network (WAN) switch, another processor-based system,and/or any combination thereof. Embodiments are not limited in thiscontext.

Computing device 120 may include at least a processor 122 and memory126. Processor 122 may be any type of processor capable of executingprograms, such as a microprocessor, digital signal processor,microcontroller, and/or the like. Processor 122 may include microcode,programmable logic or hard coded logic for execution in embodiments.Although FIG. 1 shows only one such processor 122, computing device 120may include a plurality of processors 122. Additionally, processor 122may include multiple cores, support for multiple threads, and/or thelike. Processor 122 may include microcode, programmable logic orhard-coded logic to perform operations associated with variousembodiments described herein.

Memory 126 may comprise a hard disk, a floppy disk, random access memory(RAM), read only memory (ROM), flash memory, any other type of volatilememory devices or non-volatile memory devices, or combination of theabove devices, or any other type of machine medium readable by processor122 in various embodiments. Memory 126 may store instructions and/ordata for performing program execution and other method embodiments. Insome embodiments, some embodiments may be implemented in other systemcomponents, for example, in the platform chipset or in the system's oneor more memory controllers.

VMM 110 may present to guest software an abstraction of one or more VMs104 a-n. VMM 110 may present the same or different abstractions ofphysical platform to different VMs 104 a-n. Guest software, such asguest software running on each of VM 104 a-n, may include a guest OSsuch as a guest OSs 108 a-n and various guest software applications 106a-n. Guest software may access physical resources (for instance,processor registers, memory, and I/O devices) within the VMs 104 a-n onwhich guest software is running and may perform various other functions.For example, guest software may have access to some or all registers,caches, structures, I/O devices, memory and/or the like, according tothe architecture of the processor and platform presented in VMs 104 a-n.

In one embodiment, processor 122 may control the operation of VMs 104a-n. In one embodiment, in response to a VM 104 a-n referencing a memorylocation in its virtual address space, a reference to an actual addressin the physical memory of the host machine 120 (machine physical memory)may be generated by memory management module (not shown) in VMM 110,which may be implemented in hardware (sometimes incorporated intoprocessor 122) and software (for example, in the operating system of thehost machine). In the embodiment of FIG. 1, computing device 120 mayinclude one or more I/O devices 124. Computing device 120 may includeone or more graphic control devices 128 that may be used to perform oneor more graphics functions.

FIG. 2 illustrates an example of an operating environment 200 such asmay be representative of some embodiments. More specifically, operatingenvironment 200 may include a VM environment implemented using an SR-IOVarchitecture. As shown in FIG. 2, operating environment 200 may includeVMs 210 a-n, a VMM 220, and an SR-IOV devices 230 a-n. Each of VMs 210a-n may include at least one VF driver 212 a-212 n that interact withrespective virtual functions 232 a-232 n that are implemented, forinstance, in SR-IOV devices 230 a-n. In some embodiments, at least aportion of VF drivers 212 a-n may include adaptive VF drivers. Physicalfunctions (PF) may be implemented using PF drivers 222 a-n in VMM 220,which interact with PFs 240 a-n in SR-IOV devices 230 a-n. Communicationbetween the various components is facilitated by interconnects 224. Insome embodiments, the SR-IOV architecture of operating environment 200may enable traffic to be forwarded between VMs 210 a-n without using anexternal switch.

Various systems, such as accelerators and high-performance I/O devices,may be virtualized using an SR-IOV architecture, such as thearchitecture depicted in FIG. 2. In general, SR-IOV may specify that thedevice may include a single PF 240 a-n and multiple VFs 232 a-n, suchthat each VF 232 a-n can be assigned to a VM 210 a-n directly. A VF 232a-n may appear as a virtual I/O device to the VM 210 a-n. VF driver 212a-n in VM 210 a-n may directly access VF 232 a-n MMIO space without VMM220 involvement. VF drivers 212 a-n may directly submit work torespective VFs 232 a-n and the device may process the work from variousVFs 232 a-n (or VMs 210 a-n) while providing isolation among the variousVFs 232 a-n. For instance, a VF driver 212 a-n may see a real VF 232 a-nand all of the VFs 232 a-n capabilities.

In some embodiments, VMs 210 a-n, VF drivers 212 a-n, VMM 220, VFfunctions 232 a-n, PFs 240 a-n, SR-IOV devices 230 a-n, and/orcomponents thereof may include logic implemented in hardware, software,or a combination thereof. As used in this application, the terms “logic,“component,” “layer,” “system,” “circuitry,” “decoder,” “encoder,”and/or “module” are intended to refer to a computer-related entity,either hardware, a combination of hardware and software, software, orsoftware in execution, examples of which are provided by the exemplarycomputing architecture 700. For example, a logic, circuitry, or a layermay be and/or may include, but are not limited to, a process running ona processor, a processor, a hard disk drive, multiple storage drives (ofoptical and/or magnetic storage medium), an object, an executable, athread of execution, a program, a computer, hardware circuitry,integrated circuits, a controller, application specific integratedcircuits (ASIC), programmable logic devices (PLD), digital signalprocessors (DSP), field programmable gate array (FPGA), asystem-on-a-chip (SoC), memory units, logic gates, registers,semiconductor device, chips, microchips, chip sets, software components,programs, applications, firmware, software modules, computer code,combinations of any of the foregoing, and/or the like.

In some embodiments, an adaptive VF driver, such as one or more of VFdrivers 212 a-n, may be operative to facilitate forward compatibilitywith hardware and/or software upgrades. For example, some embodimentsprovide forwarded compatibility through, among other things, adefinition of a set of basic or core features that the adaptive VFdriver may always support. To facilitate implementation, a hardwarevendor may ensure hardware interfaces remain consistent (for example,forwards and/or backwards) across product families. For example,hardware may be operative according to some embodiments to support astandard feature set for the adaptive VF. The adaptive VF driver mayoperate the standard feature set that is always available on hardwareimplementations. In addition, a physical function (PF) driver to whichthe VF binds may be operative to support an application programinterface (API) for feature negotiation. Any advanced features may benegotiated between the adaptive VF driver and an enhanced or legacy PFdriver using this feature negotiation API. In some embodiments, thesoftware protocol(s) used to communicate between the VF and PF driversmay be preserved. In various embodiments, hardware constructs that theadaptive VF driver needs to perform read and/or write operations toexecute the basic function may be preserved.

Computing devices and components thereof (for example, networking orgraphics devices) that support hardware virtualization may facilitate adistinction between configuration operations and run-time operations. Inorder to preserve forward compatibility, in some embodiments,configuration operations may be performed through the PF driver. Forexample, in some embodiments, the PF driver may be used as a proxy,rather than allowing an adaptive (or legacy) VF to configure thehardware directly. Runtime fast-path operations exercise the hardwaredirectly from the adaptive VF driver, which may be preserved accordingto some embodiments.

An adaptive VF driver provides significant technological advantages,features, and effects relative to conventional VF drivers that providesmaterial improvements in computer-related technologies, for instance,that implement virtualized environments. In one non-limiting example ofa technological advantage, adaptive VF drivers may provide networkfunction virtualization (NFV) vendors and cloud infrastructure providerswith reduced time and cost overhead of upgrading hardware in theirenvironment. In another non-limiting example of a technologicaladvantage, because an adaptive VF driver according to some embodimentsenables existing drivers to work on future products, the numerous VMsrunning in datacenters will not need to be updated for every hardwarechange. In a further non-limiting example of a technological advantage,adaptive VF drivers according to some embodiments may reduce overheadnormally incurred when updating hundreds (or thousands) of VMs.Accordingly, hardware vendors may upgrade hardware more frequently andmay allow customers to stick to a particular hardware platform. In astill further non-limiting examples of technological advantages, anadaptive VF driver according to some embodiments may reduce or eveneliminate a need to have a separate VF driver for each generation of adevice; allow reuse of current VM images for new devices, therebyreducing or eliminating costs associated with purchasing, installing andvalidating new VM images; and reduce or even eliminate a need to updateand verify VM images typically associated with new drivers or driverupgrades. Other technical advantages exist as well.

Illustrative and non-restrictive examples of technologies and/oroperating systems suitable for implementation of an adaptive VF drivermay include, without limitation, VMs, Linux kernels, kernel VM (KVM),SR-IOV devices, VF drivers, network virtualization function (NVF)drivers, data plane drivers, control plane drivers, VF base modedrivers, an Ethernet Adaptive Virtual Function driver (AVF) made byIntel® Corporation, Santa Clara, Calif., as well as other compute, I/O,peripheral, hardware, software, validation, OS, and communicationtechnologies. Embodiments are not limited in this context.

FIG. 3 illustrates an example adaptive component hierarchy to implementan architecture for an adaptive component according to some embodiments.As shown in FIG. 3, an adaptive component hierarchy 305 may include adevice ID specification layer 310. In some embodiments, the device IDspecification layer may involve specifying a standard device identifier(ID) for virtualized devices. For example, an adaptive VF driver mayinclude a single standard device identifier (ID) for all virtualizeddevices. Most I/O devices that expose a virtual function device in a VMtypically use a unique device ID to identify the type of hardware fromwhich the virtual device is derived (for example, SR-IOV devices 230a-n). In order to facilitate an adaptive VF driver operating on newerhardware from the same vendor, hardware may advertise the same (orsimilar) virtual function device ID on current and future versions ofthese devices.

In some embodiments, adaptive component hierarchy 305 may include astandard feature set layer 320. For example, an adaptive VF driver maypreserve a defined standard feature set of functionality in a hardwaredevice (for example, SR-IOV devices 230 a-n) and in software for allvirtual devices. In some embodiments, the standard feature set mayinclude a minimum set of features that the adaptive VF driver maysupport. I/O devices (for example, universal serial bus, graphics, wiredand wireless network adapters, etc.) typically support a minimum set offeatures. For example, an adaptive VF driver for a wired network adaptermay require supporting basic receive and transmit queues for data directmemory access (DMA), signaling events to software, basic statelessoffloads like checksum, segmentation offload, jumbo frames, RSS, andother features. An adaptive VF driver can also support stateful offloadslike remote DMA (RDMA), which may have their own standard feature set ofminimum required features. Hardware operative with backwardcompatibility of an adaptive VF driver may commit to preserving thehardware constructs needed to enable and support the standard featureset. Even if a hardware device is redesigned to expose advanced features(for example, updating queuing formats), the hardware device maycontinue to support the legacy features (for example, legacy queueing)so that older legacy VF drivers can continue to work on newer hardware.In addition, communication mechanism between an adaptive VF driver and aPF driver may be maintained to enable these features. Accordingly, insome embodiments, an adaptive VF driver may support a standard featureset that corresponds with a standard set of features supported by ahardware device. The hardware device may support advanced features;however, the hardware device may maintain support for the standardfeature set to facilitate compatibility with the adaptive VF driver.

In some embodiments, the defined feature set may include, withoutlimitation, checksum offload (for example, an adaptive VF driver maysupport Internet Protocol Version 4 (IPv4) header checksum generationand TCP/user datagram protocol (UDP) partial checksum generation inhardware for present and future devices); TCP segmentation offload (forexample, an adaptive VF driver may support TCP segmentation support forTCP/IPv4/Internet Protocol Version 6 (IPv6) for present and futuredevices on all its queues); multi-queue device interface (for example,an adaptive VF driver may use multiple transmit and receive queues toreduce internal overhead and to increase scalability, the presence ofmultiple queues may simplify and accelerate the process of mappingincoming and outgoing packets to a particular virtual central processingunit (vCPU)); receive side scaling (for example, an adaptive VF drivermay support spreading incoming flows to load balance across multiplevCPUs for processing using hashing, which may, among other things,reduce bottlenecks and increases cache efficiency). Embodiments are notlimited in this context.

In some embodiments, adaptive component hierarchy 305 may include aVF-PF driver dependency layer 330. In some embodiments, a hardwaredevice (for example, SR-IOV devices 230 a-n) may provide a defined (forexample, minimum) direct configuration from the adaptive VF driver intothe hardware that cannot be proxied through the PF, such as configuringof the hardware mailbox for communication with the PF, for example. Inanother example, the hardware device may contain and identify fast pathregisters and DMA formats for direct DMA access from the adaptive VFdriver. In various embodiments, a software component and/or entity maypreserve a PF-VF communication protocol definition from one generationof hardware to the next. The base features may be enabled by the PF inall cases when the enhanced VF is enabled. In some embodiments, VF-PFdriver dependency layer 330 may include an adaptive VF driver using a PFdriver as a proxy, for instance, to reduce or eliminate directconfiguration of resources or configuration of the device from theenhanced VF. In exemplary embodiments, configuration of an adaptive VFdriver may be proxied through a PF driver. In this manner, the PF canperform valid operations based on an underlying device and the adaptiveVF driver may remain agnostic of the underlying hardware.

In some embodiments, the data plane and control plane may be separatedout for the adaptive VF driver. Once that is achieved, preserving andbudgeting for future expansion of the data path may be accounted for inthe hardware direct access from the advanced VF driver. In variousembodiments, control plane or the configuration path for adaptive VFdrivers can be handled through an abstracted mailbox mechanism to a PFdriver. With the mailbox mechanism, an adaptive VF driver may beconfigured for various needs, such as a simple network interface, or atrusted interface that can configure multiple filtering rules and canget access to programming other hardware resources. In some embodiments,policies for enabling VF features may be controlled or otherwise managedvia the PF and the VMM or hypervisor (for instance, via a hypervisoradministrator). In this manner, the adaptive VF driver still remains adependent driver but can grow to expose an extremely powerful devicedepending on the policy enforced in the VMM or hypervisor.

Accordingly, in some embodiments, adaptive component hierarchy 305 mayinclude a data and control plane layer 340. In one embodiment, anadaptive VF driver may have an operating environment that include dataand control plane separation. As previously discussed, an adaptive VFdriver may rely on a PF driver for any control plane or slow-pathoperations including, without limitation, configuration, resourceallocation, reset, and/or the like. The control plane in an adaptive VFdriver can be a hardware enabled software protocol between the adaptiveVF driver and the PF driver (for example, a mailbox mechanism providedfor communication between VF and PF in some network adapters) or asoftware control path managed by a virtual switch (e.g., a VM bus(VMBus) as provided by Microsoft® Hyper-V® for communication between aservice client in the VM and the service provider in a host). The dataplane may be implemented through the hardware so that the enhanced VFhas direct fast-path access to the underlying hardware for DMA. Forexample, in a look-aside crypto implementation, security associationscan be programmed through the control plane and data that needs to beencrypted is on the data plane and may be accessed via DMA directly fromthe VM.

An advanced feature set may include features in addition to the standardfeature set. In some embodiments, features of the advanced feature setmay be negotiated with the PF driver specific to the hardware. Forexample, an adaptive VF driver may enable promiscuous mode or supportfor RDMA upon negotiation with a PF driver. Accordingly, in someembodiments, adaptive component hierarchy 305 may include an advancedfeatures access layer 350. In one embodiment, an adaptive VF driver maybe operative to negotiate and proxy advanced features/capabilities. Forexample, in some embodiments, on initialization, an adaptive VF drivermay initiate communication with a PF to request and/or query theresources available to it and the capabilities it can support. Theadaptive VF driver may send down the capabilities it would like toenable. If the adaptive VF driver is an older version and the PFsupports additional capabilities, then the adaptive VF driver still getsthe standard feature set of capabilities that it requested. This allowsthe older adaptive VF driver to be able to run on a newer PF. If theadaptive VF driver is a newer driver and the underlying hardware cansupport only a subset of the capabilities the adaptive VF driver cansupport, the PF may only enable the standard feature set, therebyallowing the adaptive VF driver to run on the older PF and hardware.

In some embodiments, an adaptive VF driver may attempt to negotiate witha PF for advanced capabilities beyond the standard feature set that itcan support. In this manner, if the PF is unable to support advancedcapability, the adaptive VF driver can still continue to work with thestandard feature set. If the PF can support the advanced features thenthe adaptive VF driver may selectively enable them.

An adaptive VF driver according to some embodiments, including adaptivecomponent hierarchy 305, provides technological advantages compared toconventional VF drivers. For instance, an early iteration of an Intel®VF driver referred to as version “igbvf” provided no receive sidescaling (RSS) or multi-queue support. With version “ixgbevf,” the Intel®VF driver moved to support 2 queue RSS capability. With version“i40evf,” the Intel® VF driver can scale up to 64 queues on “X722”devices. All the VF devices supported checksum and transmission controlprotocol (TCP) segmentation offload capability. With version “i40evf”came support of features for network function virtualization (NFV) andenablement to support remote direct memory access (RDMA) capabilities inthe VF. Transmit (TX) checksum offload and TCP segmentation offload(TSO) for tunnels support were added both on “i40evf” and “ixgbevf”drivers. With these updates, new design patterns emerged with respect toVF drivers. Most advances were in the control plane, whereas the dataplane can be kept fairly stable, although it has been scaling overgenerations. This led to separation of data plane and control planecapabilities. Further, it was recognized that as long as the data planeor “hotpath” access can be budgeted for future growth, the rest of theslow path configuration can be achieved through an indirect mechanism,for instance, via communication with the physical function (PF) driver.

In some embodiments, a particular implementation of an adaptive VFdriver may have various design considerations. In one embodiment, forinstance, an adaptive VF driver for SR-IOV enabled interfaces mayinclude a dependent driver that negotiates advanced features with thecorresponding PF driver. In order to achieve fast DMA, for example, andto get throughput comparable to that of the PF, direct memory access todevice registers in the data path/hot path may be implemented. Otherfeatures may be determined via negotiation with the PF driver.

In some embodiments, hardware components may be operative to reserveonly the data plane direct access and, for the rest, support a generichardware mailbox (for example, to leave opportunity for expansion). Insome embodiments, a virtual channel may be supported with capabilitynegotiation between PF and VF driver on top of the hardware mailbox.This can be expanded with more capabilities depending on use-case and topreserve the base capabilities that all PFs and VFs must support such assingle layer checksum, TSO, RSS, and/or the like.

As more and more features are added to the adaptive VF driver,regression testing may be performed to determine whether the VF canstill work with the standard feature set. Accordingly, in someembodiments, the standard feature set (for example, a bare minimumfeature set for what is needed during hot path access) may beimplemented. Additional features may be proxied through the PF driver.The PF driver may be queried by the adaptive VF driver responsive tovarious events, such as a setup change, a policy change, errorcondition, additional resource requirements (for example, the adaptiveVF driver requires additional resources), and/or the like. If there is aflow or process that needs to be directed or dropped, the adaptive VFdriver may query the PF to set it up. In this manner, the setup may beabstracted from the underlying device specific details and thereforemakes the adaptive VF driver as substantially if not completely hardwareagnostic.

In some embodiments, concise and/or expandable hotpath registerdefinitions may be preserved over hardware generations. In variousembodiments, the adaptive VF driver may use an abstracted hardwaremailbox to the PF driver, for example, that can be built upon forextended capability negotiation. In one embodiment, a single expandableadaptive VF driver may be maintained. For instance, patches on thesingle expandable adaptive VF driver may be tested so as to not breakforward or backward compatibility. Since the adaptive VF driver may bean expandable driver, it is likely that more features will be added inthe future. As such, functionalities supported in one generation ofsilicon may not be supported on all hardware. Accordingly, embodimentsprovide processes for adaptive VF driver negotiation with the PF driverwith respect to what can be enabled on a given device to avoid orcompletely eliminating breaking the base mode compatibility model forfuture devices.

FIG. 4 illustrates an example of an operating environment 400 that maybe representative of some embodiments. In general, FIG. 4 mayillustrates an example of use of single adaptive VF driver or aplurality of different VF drivers that can be used with various PFdrivers that configure a different device (for example, differentgenerations of a networking adapter) according to various embodiments.As shown in FIG. 4, operating environment 400 may include a virtualizedcomputing environment implemented through apparatus 405. In someembodiments, apparatus 405 may include a single compute node. In otherembodiments, apparatus 405 may include a plurality of compute nodes.Apparatus 405 may include VMs 410 a-n, VMM (or hypervisor) 430, anddevices 450 a-n. In some embodiments, any of devices 450 a-n may includevarious physical hardware components of apparatus 405, such as anetworking device, I/O device, and/or the like. In some embodiments,devices 450 a-n may include different hardware configurations, features,and/or the like. For example, one or more of devices 450 a-n may includea different hardware generation of a same or similar device (forinstance, a network interface controller (NIC)).

Each of VMs 410 a, 410 b, and 410 n may be associated with adaptive VF(AVF) drivers 420 a, 420 b, and 420 n to control devices 450 a, 450 b,and 450 n, respectively. Although each VM 410 a-n is depicted as beingassociated with a single AVF 420 a-n, embodiments are not so limited, asVMs 410 a-n may be associated with a plurality of AVFs 420 a-n. VMM 430may include a PF 440 a, 440 b, and 440 n associated with a device 450 a,450 b, and 450 n, respectively. In some embodiments, each of AVFs 420a-n may operate with a plurality of VMs 410 a-n, a plurality of PFs 440a-n, and/or a plurality of devices 450 a-n. In this manner, time andcost overheads may be reduced for upgrading hardware components (forexample, devices 450 a-n) for VMs 410 a-n.

In some embodiments, each of AVFs 420 a-n may be the same AVF, forexample, including the same or substantially the same hardware,software, logic, and/or the like for operating AVFs 420 a-n. In otherembodiments, at least a portion of AVFs 420 a-n my include differentAVFs, for example, that include different hardware, software, logic,and/or the like for operating AVFs 420 a-n. In this manner, for example,AVFs 420 a-n may be configured, selected, managed, or otherwise operatedfor specific devices 450 a-n. In various embodiments, at least a portionof AVFs 420 a-n may be configured, operated, and/or the like accordingto a two-driver model. In the two-driver model, a frozen feature VF basedriver and a separate adaptive VF driver may be used that enables atrusted virtual function. In some embodiments, the two-driver model maybe efficient, for example, for NFV environments.

Included herein are one or more logic flows representative of exemplarymethodologies for performing novel aspects of the disclosedarchitecture. While, for purposes of simplicity of explanation, the oneor more methodologies shown herein are shown and described as a seriesof acts, those skilled in the art will understand and appreciate thatthe methodologies are not limited by the order of acts. Some acts may,in accordance therewith, occur in a different order and/or concurrentlywith other acts from that shown and described herein. For example, thoseskilled in the art will understand and appreciate that a methodologycould alternatively be represented as a series of interrelated states orevents, such as in a state diagram. Moreover, not all acts illustratedin a methodology may be required for a novel implementation.

A logic flow may be implemented in software, firmware, hardware, or anycombination thereof. In software and firmware embodiments, a logic flowmay be implemented by computer executable instructions stored on anon-transitory computer readable medium or machine readable medium, suchas an optical, magnetic or semiconductor storage. The embodiments arenot limited in this context.

FIG. 5 illustrates an embodiment of a logic flow 500. Logic flow 500 maybe representative of some or all of the operations executed by one ormore embodiments described herein, such as operating environments 100and 200 and/or apparatus 405. In some embodiments, logic flow 500 may berepresentative of some or all of the operations of a performanceanalysis process.

At block 502, logic flow 500 may initialize adaptive VF. For example, VM410 a may initialize AVF 420 a corresponding to functionality of device450 a. Logic flow 500 may initiate communication between the VF and a PFat block 504. For example, AVF 420 a may initiate communication with PF440 a. In some embodiments, on initialization, an adaptive VF driver mayinitiate communication with a PF to request and/or query the resourcesavailable to it and the capabilities it can support. In variousembodiments, adaptive VF driver may use a PF driver as a proxy, forinstance, to reduce or eliminate direct configuration of resources orconfiguration of the device from the enhanced VF.

At block 506, logic flow 500 VF requested feature set is provided to thePF. For example, AVF 420 a may provide PF 440 a with a requested featureset of features that AVF 420 a intends to enable. In some embodiments,the requested feature set may include features of a standard feature setand/or features of an advanced feature set. Logic flow 500 may activatea standard feature set at block 508. For example, AVF 420 a may operatea standard (for instance, minimum or basic) feature set that is alwaysavailable on hardware implementations. For example, an adaptive VFdriver may preserve a defined standard feature set of functionality in ahardware device (for example, SR-IOV devices 230 a-n) and in softwarefor all virtual devices. In some embodiments, the standard feature setmay include a minimum set of features that the adaptive VF driver maysupport.

At block 510, logic flow 500 may determine whether advanced features areto be activated. For example, an advanced feature set may includefeatures in addition to the standard feature set. In some embodiments,features of the advanced feature set may be negotiated with the PFdriver specific to the hardware. If advanced features are not to beactivated, logic flow 500 may end at block 514 and the AVF may use thestandard feature set. If advanced features are to be activated, logicflow may activate advanced feature set at block 512.

FIG. 6 illustrates an example of a storage medium 600. Storage medium600 may comprise an article of manufacture. In some examples, storagemedium 600 may include any non-transitory computer readable medium ormachine readable medium, such as an optical, magnetic or semiconductorstorage. Storage medium 600 may store various types of computerexecutable instructions, such as instructions to implement logic flow500. Examples of a computer readable or machine readable storage mediummay include any tangible media capable of storing electronic data,including volatile memory or non-volatile memory, removable ornon-removable memory, erasable or non-erasable memory, writeable orre-writeable memory, and so forth. Examples of computer executableinstructions may include any suitable type of code, such as source code,compiled code, interpreted code, executable code, static code, dynamiccode, object-oriented code, visual code, and the like. The examples arenot limited in this context.

FIG. 7 illustrates an example computing platform 700. In some examples,as shown in FIG. 7, computing platform 700 may include a processingcomponent 740, other platform components or a communications interface760. According to some examples, computing platform 700 may beimplemented in a computing device such as a server in a system such as adata center. Embodiments are not limited in this context.

According to some examples, processing component 740 may executeprocessing operations or logic for operating environments 100 and 200,apparatus 405, and/or storage medium 600. Processing component 740 mayinclude various hardware elements, software elements, or a combinationof both. Examples of hardware elements may include devices, logicdevices, components, processors, microprocessors, circuits, processorcircuits, circuit elements (e.g., transistors, resistors, capacitors,inductors, and so forth), integrated circuits, application specificintegrated circuits (ASIC), programmable logic devices (PLD), digitalsignal processors (DSP), field programmable gate arrays (FPGAs), memoryunits, logic gates, registers, semiconductor devices, chips, microchips,chip sets, and so forth. Examples of software elements may includesoftware components, programs, applications, computer programs,application programs, device drivers, system programs, softwaredevelopment programs, machine programs, operating system software,middleware, firmware, software modules, routines, subroutines,functions, methods, procedures, software interfaces, application programinterfaces (API), instruction sets, computing code, computer code, codesegments, computer code segments, words, values, symbols, or anycombination thereof. Determining whether an example is implemented usinghardware elements and/or software elements may vary in accordance withany number of factors, such as desired computational rate, power levels,heat tolerances, processing cycle budget, input data rates, output datarates, memory resources, data bus speeds and other design or performanceconstraints, as desired for a given example.

In some examples, other platform components 750 may include commoncomputing elements, such as one or more processors, multi-coreprocessors, co-processors, memory units, chipsets, controllers,peripherals, interfaces, oscillators, timing devices, video cards, audiocards, multimedia input/output (I/O) components (e.g., digitaldisplays), power supplies, and so forth. Examples of memory units mayinclude without limitation various types of computer readable andmachine readable storage media in the form of one or more higher speedmemory units, such as read-only memory (ROM), random-access memory(RAM), dynamic RAM (DRAM), double data rate DRAM (DDRAM), synchronousDRAM (SDRAM), static RAM (SRAM), programmable ROM (PROM), erasableprogrammable ROM (EPROM), electrically erasable programmable ROM(EEPROM), flash memory, polymer memory such as ferroelectric polymermemory, ovonic memory, phase change or ferroelectric memory,silicon-oxide-nitride-oxide-silicon (SONOS) memory, magnetic or opticalcards, an array of devices such as redundant array of independent disks(RAID) drives, solid state memory devices (e.g., USB memory), solidstate drives (SSD) and any other type of storage media suitable forstoring information.

In some examples, communications interface 760 may include logic and/orfeatures to support a communication interface. For these examples,communications interface 760 may include one or more communicationinterfaces that operate according to various communication protocols orstandards to communicate over direct or network communication links.Direct communications may occur via use of communication protocols orstandards described in one or more industry standards (includingprogenies and variants) such as those associated with the PCI Expressspecification. Network communications may occur via use of communicationprotocols or standards such those described in one or more Ethernetstandards promulgated by the Institute of Electrical and ElectronicsEngineers (IEEE). For example, one such Ethernet standard may includeIEEE 802.3-2012, carrier sense multiple access with collision detection(CSMA/CD) access method and physical layer specifications, Published inDecember 2012 (hereinafter “IEEE 802.3”). Network communication may alsooccur according to one or more OpenFlow specifications such as theOpenFlow Hardware Abstraction API Specification. Network communicationsmay also occur according to Infiniband Architecture Specification,Volume 1, Release 1.3, published in March 2015 (“the InfinibandArchitecture Specification”).

Computing platform 700 may be part of a computing device that may be,for example, a server, a server array or server farm, a web server, anetwork server, an Internet server, a work station, a mini-computer, amain frame computer, a supercomputer, a network appliance, a webappliance, a distributed computing system, multiprocessor systems,processor-based systems, or combination thereof. Accordingly, functionsand/or specific configurations of computing platform 700 describedherein, may be included or omitted in various embodiments of computingplatform 700, as suitably desired.

The components and features of computing platform 700 may be implementedusing any combination of discrete circuitry, ASICs, logic gates and/orsingle chip architectures. Further, the features of computing platform700 may be implemented using microcontrollers, programmable logic arraysand/or microprocessors or any combination of the foregoing wheresuitably appropriate. It is noted that hardware, firmware and/orsoftware elements may be collectively or individually referred to hereinas “logic” or “circuit.”

It should be appreciated that the exemplary computing platform 700 shownin the block diagram of FIG. 7 may represent one functionallydescriptive example of many potential implementations. Accordingly,division, omission or inclusion of block functions depicted in theaccompanying figures does not infer that the hardware components,circuits, software and/or elements for implementing these functionswould necessarily be divided, omitted, or included in embodiments.

One or more aspects of at least one embodiment may be implemented byrepresentative instructions stored on a machine-readable medium whichrepresents various logic within the processor, which when read by amachine causes the machine to fabricate logic to perform the techniquesdescribed herein. Such representations, known as “IP cores” may bestored on a tangible, machine readable medium and supplied to variouscustomers or manufacturing facilities to load into the fabricationmachines that actually make the logic or processor. Some embodiments maybe implemented, for example, using a machine-readable medium or articlewhich may store an instruction or a set of instructions that, ifexecuted by a machine, may cause the machine to perform a method and/oroperations in accordance with the embodiments. Such a machine mayinclude, for example, any suitable processing platform, computingplatform, computing device, processing device, computing system,processing system, computer, processor, or the like, and may beimplemented using any suitable combination of hardware and/or software.The machine-readable medium or article may include, for example, anysuitable type of memory unit, memory device, memory article, memorymedium, storage device, storage article, storage medium and/or storageunit, for example, memory, removable or non-removable media, erasable ornon-erasable media, writeable or re-writeable media, digital or analogmedia, hard disk, floppy disk, compact disk read only memory (CD-ROM),compact disk recordable (CD-R), compact disk rewriteable (CD-RW),optical disk, magnetic media, magneto-optical media, removable memorycards or disks, various types of digital versatile disk (DVD), a tape, acassette, or the like. The instructions may include any suitable type ofcode, such as source code, compiled code, interpreted code, executablecode, static code, dynamic code, encrypted code, and the like,implemented using any suitable high-level, low-level, object-oriented,visual, compiled and/or interpreted programming language.

The following include non-limiting example embodiments:

Example 1 is an apparatus, comprising at least one memory, at least oneprocessor, and logic to implement a virtual machine (VM), at least aportion of the logic comprised in hardware coupled to the at least onememory and the at least one processor, the logic to initialize anadaptive virtual function (VF) driver to facilitate communicationbetween the VM and a physical device to be virtualized by a hypervisoroperating on the apparatus, establish communication between the adaptiveVF driver and a physical function (PF) driver of the hypervisor for thephysical device, activate a standard feature set for the adaptive VFdriver to execute on a PF of the physical device, and negotiateactivation of an advanced feature set for the adaptive VF driver toexecute on the PF, the adaptive VF driver to provide the advancedfeature set to the PF, the PF to activate each feature of the advancedfeature set supported by the PF.

Example 2 is the apparatus of Example 1, the standard feature setcomprising a minimum set of features required for operation of theadaptive VF driver.

Example 3 is the apparatus of Example 1, the standard feature setcomprising at least one of checksum offload, transmission controlprotocol (TCP) segmentation offload, multi-queue device interface, orreceive side scaling.

Example 4 is the apparatus of Example 1, the PF driver operative as aproxy for the adaptive VF driver to configure the physical device.

Example 5 is the apparatus of Example 1, the PF driver to providecontrol plane functionality for the physical device to the adaptive VFdriver.

Example 6 is the apparatus of Example 5, comprising a control planecomprising a software protocol between the adaptive VF driver and the PFdriver.

Example 7 is the apparatus of Example 5, the control plane comprising asoftware control path managed by a virtual switch.

Example 8 is the apparatus of Example 1, the logic to disable eachfeature of the advanced feature set not supported by the PF.

Example 9 is the apparatus of Example 1, the logic to providecommunication between the physical device and the PF via a hardwaremailbox process.

Example 10 is the apparatus of Example 1, the logic to provide datacommunication between the adaptive VF driver and the physical device viadirect memory access (DMA).

Example 11 is the apparatus of Example 1, the logic to provide datacommunication between the adaptive VF driver and the physical device viafast path registers.

Example 12 is a system, comprising the apparatus according to any ofExamples 1-11, and at least one network interface.

Example 13 is a method to implement a virtual machine (VM), the methodcomprising initializing an adaptive virtual function (VF) driver tofacilitate communication between the VM and a physical device to bevirtualized by a hypervisor, establishing communication between theadaptive VF driver and a physical function (PF) driver of the hypervisorfor the physical device, activating a standard feature set for theadaptive VF driver to execute on a PF of the physical device, andnegotiating activation of an advanced feature set for the adaptive VFdriver to execute on the PF, the adaptive VF driver to provide theadvanced feature set to the PF, the PF to activate each feature of theadvanced feature set supported by the PF.

Example 14 is the method of Example 13, the standard feature setcomprising a minimum set of features required for operation of theadaptive VF driver.

Example 15 is the method of Example 13, the standard feature setcomprising at least one of checksum offload, transmission controlprotocol (TCP) segmentation offload, multi-queue device interface, orreceive side scaling.

Example 16 is the method of Example 13, the PF driver operative as aproxy for the adaptive VF driver to configure the physical device.

Example 17 is the method of Example 13, the PF driver to provide controlplane functionality for the physical device to the adaptive VF driver.

Example 18 is the apparatus of Example 17, comprising a control planecomprising a software protocol between the adaptive VF driver and the PFdriver.

Example 19 is the apparatus of Example 17, the control plane comprisinga software control path managed by a virtual switch.

Example 20 is the method of Example 13, comprising disabling eachfeature of the advanced feature set not supported by the PF.

Example 21 is the method of Example 13, comprising providingcommunication between the physical device and the PF via a hardwaremailbox process.

Example 22 is the method of Example 13, comprising providing datacommunication between the adaptive VF driver and the physical device viadirect memory access (DMA).

Example 23 is the method of Example 13, comprising providing datacommunication between the adaptive VF driver and the physical device viafast path registers.

Example 24 is a non-transitory computer-readable storage medium thatstores computer-executable instructions for execution by processingcircuitry of a computing device, the computer-executable instructions,when executed, to cause the computing device to initialize an adaptivevirtual function (VF) driver to facilitate communication between the VMand a physical device to be virtualized by a hypervisor operating on thecomputing device, establish communication between the adaptive VF driverand a physical function (PF) driver of the hypervisor for the physicaldevice, activate a standard feature set for the adaptive VF driver toexecute on a PF of the physical device, and negotiate activation of anadvanced feature set for the adaptive VF driver to execute on the PF,the adaptive VF driver to provide the advanced feature set to the PF,the PF to activate each feature of the advanced feature set supported bythe PF.

Example 25 is the non-transitory computer-readable storage medium ofExample 24, the standard feature set comprising a minimum set offeatures required for operation of the adaptive VF driver.

Example 26 is the non-transitory computer-readable storage medium ofExample 24, the standard feature set comprising at least one of checksumoffload, transmission control protocol (TCP) segmentation offload,multi-queue device interface, or receive side scaling.

Example 27 is the non-transitory computer-readable storage medium ofExample 24, the PF driver operative as a proxy for the adaptive VFdriver to configure the physical device.

Example 28 is the non-transitory computer-readable storage medium ofExample 24, the PF driver to provide control plane functionality for thephysical device to the adaptive VF driver.

Example 29 is the non-transitory computer-readable storage medium ofExample 28, comprising a control plane comprising a software protocolbetween the adaptive VF driver and the PF driver.

Example 30 is the non-transitory computer-readable storage medium ofExample 28, the control plane comprising a software control path managedby a virtual switch.

Example 31 is the non-transitory computer-readable storage medium ofExample 24, the computer-executable instructions, when executed, tocause the computing device to disable each feature of the advancedfeature set not supported by the PF.

Example 32 is the non-transitory computer-readable storage medium ofExample 24, the computer-executable instructions, when executed, tocause the computing device to provide communication between the physicaldevice and the PF via a hardware mailbox process.

Example 33 is the non-transitory computer-readable storage medium ofExample 24, the computer-executable instructions, when executed, tocause the computing device to provide data communication between theadaptive VF driver and the physical device via direct memory access(DMA).

Example 34 is the non-transitory computer-readable storage medium ofExample 24, the computer-executable instructions, when executed, tocause the computing device to provide data communication between theadaptive VF driver and the physical device via fast path registers.

Example 35 is an apparatus, comprising a virtual function (VF)initialization means to initialize an adaptive VF driver to facilitatecommunication between the VM and a physical device to be virtualized bya hypervisor operating on the apparatus, a physical function (PF)control means to control operation of a PF driver associated with thephysical device, a VF communication means to establish communicationbetween the adaptive VF driver and a PF driver of the hypervisor for thephysical device, and a VF feature activation means to activate astandard feature set for the adaptive VF driver to execute on a PF ofthe physical device, and negotiate activation of an advanced feature setfor the adaptive VF driver to execute on the PF, the adaptive VF driverto provide the advanced feature set to the PF, the PF to activate eachfeature of the advanced feature set supported by the PF.

Example 36 is the apparatus of Example 35, the standard feature setcomprising a minimum set of features required for operation of theadaptive VF driver.

Example 37 is the apparatus of Example 35, the standard feature setcomprising at least one of checksum offload, transmission controlprotocol (TCP) segmentation offload, multi-queue device interface, orreceive side scaling.

Example 38 is the apparatus of Example 35, the PF control means tooperate the PF driver as a proxy for the adaptive VF driver to configurethe physical device.

Example 39 is the apparatus of Example 35, the PF control means tooperate the PF driver to provide control plane functionality for thephysical device to the adaptive VF driver.

Example 38 is the apparatus of Example 35, the PF control means tooperate the PF driver as a proxy for the adaptive VF driver to configurethe physical device.

Example 39 is the apparatus of Example 35, the PF control means tooperate the PF driver to provide control plane functionality for thephysical device to the adaptive VF driver.

Example 40 is the apparatus of Example 39, comprising a control planecomprising a software protocol between the adaptive VF driver and the PFdriver.

Example 41 is the apparatus of Example 39, the control plane comprisinga software control path managed by a virtual switch.

Example 42 is the apparatus of Example 35, the VF feature activationmeans to disable each feature of the advanced feature set not supportedby the PF.

Example 43 is the apparatus of Example 35, the VF communication means toprovide communication between the physical device and the PF via ahardware mailbox process.

Example 44 is the apparatus of Example 35, the VF communication means toprovide data communication between the adaptive VF driver and thephysical device via direct memory access (DMA).

Example 45 is the apparatus of Example 35, the VF communication means toprovide data communication between the adaptive VF driver and thephysical device via fast path registers.

Example 46 is a system, comprising the apparatus according to any ofexamples 35-45, and at least one network interface.

Numerous specific details have been set forth herein to provide athorough understanding of the embodiments. It will be understood bythose skilled in the art, however, that the embodiments may be practicedwithout these specific details. In other instances, well-knownoperations, components, and circuits have not been described in detailso as not to obscure the embodiments. It can be appreciated that thespecific structural and functional details disclosed herein may berepresentative and do not necessarily limit the scope of theembodiments.

Some embodiments may be described using the expression “coupled” and“connected” along with their derivatives. These terms are not intendedas synonyms for each other. For example, some embodiments may bedescribed using the terms “connected” and/or “coupled” to indicate thattwo or more elements are in direct physical or electrical contact witheach other. The term “coupled,” however, may also mean that two or moreelements are not in direct contact with each other, but yet stillco-operate or interact with each other.

Unless specifically stated otherwise, it may be appreciated that termssuch as “processing,” “computing,” “calculating,” “determining,” or thelike, refer to the action and/or processes of a computer or computingsystem, or similar electronic computing device, that manipulates and/ortransforms data represented as physical quantities (e.g., electronic)within the computing system's registers and/or memories into other datasimilarly represented as physical quantities within the computingsystem's memories, registers or other such information storage,transmission or display devices. The embodiments are not limited in thiscontext.

It should be noted that the methods described herein do not have to beexecuted in the order described, or in any particular order. Moreover,various activities described with respect to the methods identifiedherein can be executed in serial or parallel fashion.

Although specific embodiments have been illustrated and describedherein, it should be appreciated that any arrangement calculated toachieve the same purpose may be substituted for the specific embodimentsshown. This disclosure is intended to cover any and all adaptations orvariations of various embodiments. It is to be understood that the abovedescription has been made in an illustrative fashion, and not arestrictive one. Combinations of the above embodiments, and otherembodiments not specifically described herein will be apparent to thoseof skill in the art upon reviewing the above description. Thus, thescope of various embodiments includes any other applications in whichthe above compositions, structures, and methods are used.

Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described above.Rather, the specific features and acts described above are disclosed asexample forms of implementing the claims.

What is claimed is:
 1. An apparatus, comprising: at least one memory; atleast one processor; and logic to implement a virtual machine (VM), atleast a portion of the logic comprised in hardware coupled to the atleast one memory and the at least one processor, the logic to:initialize an adaptive virtual function (VF) driver to facilitatecommunication between the VM and a physical device to be virtualized bya hypervisor operating on the apparatus; establish communication betweenthe adaptive VF driver and a physical function (PF) driver of thehypervisor for the physical device; activate a standard feature set forthe adaptive VF driver to execute on a PF of the physical device; andnegotiate activation of an advanced feature set for the adaptive VFdriver to execute on the PF, the adaptive VF driver to provide theadvanced feature set to the PF, the PF to activate each feature of theadvanced feature set supported by the PF.
 2. The apparatus of claim 1,the standard feature set comprising a minimum set of features requiredfor operation of the adaptive VF driver.
 3. The apparatus of claim 1,the standard feature set comprising at least one of checksum offload,transmission control protocol (TCP) segmentation offload, multi-queuedevice interface, or receive side scaling.
 4. The apparatus of claim 1,the PF driver operative as a proxy for the adaptive VF driver toconfigure the physical device.
 5. The apparatus of claim 1, the PFdriver to provide control plane functionality for the physical device tothe adaptive VF driver.
 6. The apparatus of claim 5, comprising acontrol plane comprising a software protocol between the adaptive VFdriver and the PF driver.
 7. The apparatus of claim 5, the control planecomprising a software control path managed by a virtual switch.
 8. Theapparatus of claim 1, the logic to disable each feature of the advancedfeature set not supported by the PF.
 9. The apparatus of claim 1, thelogic to provide communication between the physical device and the PFvia a hardware mailbox process.
 10. The apparatus of claim 1, the logicto provide data communication between the adaptive VF driver and thephysical device via at least one of direct memory access (DMA) or fastpath registers.
 11. A method to implement a virtual machine (VM), themethod comprising: initializing an adaptive virtual function (VF) driverto facilitate communication between the VM and a physical device to bevirtualized by a hypervisor; establishing communication between theadaptive VF driver and a physical function (PF) driver of the hypervisorfor the physical device; activating a standard feature set for theadaptive VF driver to execute on a PF of the physical device; andnegotiating activation of an advanced feature set for the adaptive VFdriver to execute on the PF, the adaptive VF driver to provide theadvanced feature set to the PF, the PF to activate each feature of theadvanced feature set supported by the PF.
 12. The method of claim 11,the standard feature set comprising a minimum set of features requiredfor operation of the adaptive VF driver.
 13. The method of claim 11, thestandard feature set comprising at least one of checksum offload,transmission control protocol (TCP) segmentation offload, multi-queuedevice interface, or receive side scaling.
 14. The method of claim 11,the PF driver operative as a proxy for the adaptive VF driver toconfigure the physical device.
 15. The method of claim 11, the PF driverto provide control plane functionality for the physical device to theadaptive VF driver.
 16. The method of claim 15, comprising a controlplane comprising a software protocol between the adaptive VF driver andthe PF driver.
 17. The method of claim 15, the control plane comprisinga software control path managed by a virtual switch.
 18. The method ofclaim 11, comprising disabling each feature of the advanced feature setnot supported by the PF.
 19. The method of claim 11, comprisingproviding communication between the physical device and the PF via ahardware mailbox process.
 20. The method of claim 11, comprisingproviding data communication between the adaptive VF driver and thephysical device via at least one of direct memory access (DMA) or fastpath registers.
 21. A non-transitory computer-readable storage mediumthat stores computer-executable instructions for execution by processingcircuitry of a computing device, the computer-executable instructions,when executed, to cause the computing device to: initialize an adaptivevirtual function (VF) driver to facilitate communication between avirtual machine (VM) and a physical device to be virtualized by ahypervisor operating on the computing device; establish communicationbetween the adaptive VF driver and a physical function (PF) driver ofthe hypervisor for the physical device; activate a standard feature setfor the adaptive VF driver to execute on a PF of the physical device;and negotiate activation of an advanced feature set for the adaptive VFdriver to execute on the PF, the adaptive VF driver to provide theadvanced feature set to the PF, the PF to activate each feature of theadvanced feature set supported by the PF.
 22. The non-transitorycomputer-readable storage medium of claim 21, the standard feature setcomprising a minimum set of features required for operation of theadaptive VF driver.
 23. The non-transitory computer-readable storagemedium of claim 21, the standard feature set comprising at least one ofchecksum offload, transmission control protocol (TCP) segmentationoffload, multi-queue device interface, or receive side scaling.
 24. Thenon-transitory computer-readable storage medium of claim 21, the PFdriver operative as a proxy for the adaptive VF driver to configure thephysical device.
 25. The non-transitory computer-readable storage mediumof claim 21, the PF driver to provide control plane functionality forthe physical device to the adaptive VF driver.